Smart Solar International Inc, a spin-off from the University of Tokyo, will release a uniaxial-tracking light condensing system equipped with triple-junction compound photovoltaic (PV) cells in July 2012.
The maximum output power of the module integrated with its pedestal is 200W (maximum output voltage: 50V, maximum output current: 4A). Its price is ¥84,000 (approx US$1,007).
The triple-junction compound PV cell has a structure in which InGaAs (indium gallium arsenide) and InGaP (indium gallium phosphide) are accumulated on a Ge (germanium) substrate. Its cell conversion efficiency is 32% without light condensing and 36% at the time of 100-500x light condensing.
When the module is made by using the cell, the module conversion efficiency is 23% at the time of 30-50x light condensing, which Smart Solar International claims is a world record.
The module consists of (1) the main body made by arranging 1 x 1cm cells in a straight line, (2) a mirror that collects light, (3) motor used to move the mirror, (4) mechanism that cools the cells, (5) pedestal, etc. The size of the mirror is 200 x 60cm. And the weight of the entire module is 15kg. The cooling mechanism was developed by using the principle of siphon and does not require a pump .